Tikka rings are not the highest quality product out there, so my scope was slipping while at deer camp. Being a complete novice I got it back where I wanted it and cranked on those screws. Whoops. Cracked something internally and instead of increasing magnification, the reticle spun. I put it back to the lowest power and shot a deer the following morning (40 yard shot so it would have to have been majorly off to miss). Needless to say when I got home I found a reputable gunsmith!